I found the hardest part of becoming a leader is trusting my own judgment, intuitions and decisions.
The "Disney" quates for managers like "it's the team that succeeds" and "you don't accomplish tasks, you'r team does" led me to disregard my experience and allow engineers to dictate most of the design, which turned out rubbish.
I knew better, had solid arguments for my design, yet I let the team proceed with an inferior solution in the spirit of enablement.
The customer payed the price.
